diff mbox

[3/7] dm-mpath: Document a locking assumption

Message ID 951713a6-d3ff-43ac-489b-613944a2b085@sandisk.com (mailing list archive)
State Rejected, archived
Delegated to: Mike Snitzer
Headers show

Commit Message

Bart Van Assche Nov. 15, 2016, 11:33 p.m. UTC 
Document that __pg_init_all_paths() must be called with
multipath.lock held.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
---
 drivers/md/dm-mpath.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Mike Snitzer Nov. 18, 2016, 12:07 a.m. UTC | #1 
On Tue, Nov 15 2016 at  6:33pm -0500,
Bart Van Assche <bart.vanassche@sandisk.com> wrote:

> Document that __pg_init_all_paths() must be called with
> multipath.lock held.
> 
> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
> ---
>  drivers/md/dm-mpath.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
> index e477af8..f1e226d 100644
> --- a/drivers/md/dm-mpath.c
> +++ b/drivers/md/dm-mpath.c
> @@ -348,6 +348,8 @@ static int __pg_init_all_paths(struct multipath *m)
>  	struct pgpath *pgpath;
>  	unsigned long pg_init_delay = 0;
>  
> +	lockdep_assert_held(&m->lock);
> +
>  	if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
>  		return 0;
>  
> -- 
> 2.10.1
> 

The leading underscores document the need for locking
(__pg_init_all_paths vs pg_init_all_paths).

--
dm-devel mailing list
dm-devel@redhat.com
https://www.redhat.com/mailman/listinfo/dm-devel
diff mbox

Patch

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e477af8..f1e226d 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -348,6 +348,8 @@  static int __pg_init_all_paths(struct multipath *m)
 	struct pgpath *pgpath;
 	unsigned long pg_init_delay = 0;
 
+	lockdep_assert_held(&m->lock);
+
 	if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
 		return 0;